Influence of integrated nutrient management on productivity, nutrient uptake and economics of maize (Zea mays)–yellow sarson (Brassica rapa) cropping system under rainfed mid hill condition

A field experiment was conducted during 2010–12 at Kalingpong, West Bengal, to study effect of doses of chemical fertilizers along with organic sources of nutrients on growth, yield and economics of maize (Zea mays L.)–yellow sarson [Brassica rapa (L.) Var. Yellow sarson] cropping system under mid hill condition. Maximum grain and stover yields of maize were obtained with of 150% recommended dose of fertilizers (RDF) (maize) + 25% RDF (yellow sarson) (5.1 and 9.3 t/ha respectively) and was statistically at par with the application of 100% RDF (maize) + 50% RDF (yellow sarson) (5.0 and 9.3 t/ha respectively). Amongst the organic sources of nutrients, more grain and stover yields were recorded with application of FYM @ 2.5 t/ha + vermicompost @ 1.25 t/ha + forest litter @ 2.5 t/ha and were at par with vermicompost @ 2.5 t/ha + forest litter @ 5 t/ha, and was significantly superior to rest of the treatments. Seed yield of yellow sarson was not influenced by chemical fertilizers. Significant result was registered with stover yield, and maximum was recorded with 150% RDF (maize) + 25% RDF (yellow sarson) (3.2 t/ha), and was at par with 50% RDF (maize) + 100% RDF (yellow sarson) (3.0 t/ha). Amongst the organic sources, more seed and stover yields were recorded with application of FYM @ 2.5 t/ha + vermicompost @1.25 t/ha + forest litter @ 2.5 t/ha (1.9 t/ha). Nutrient uptake pattern was also influenced by various sources under maize–yellow sarson cropping system. The productivity of cropping system was positively influenced by various inorganic and organic treatments. Maximum maize-equivalent yield (MEY) was recorded with 50% RDF (maize) + 100% RDF (yellow sarson) (5.3 t/ha), and was at par with the 100% RDF (maize) + 50% RDF (yellow sarson) and 150% RDF (maize) + 25% RDF (yellow sarson). The highest MEY of 5.1 t/ha was recorded with FYM @ 2.5 t/ha + vermicompost @ 1.25 t/ha + forest litter @ 2.5 t/ha, being at par with vermicompost @ 2.5 t/ha + forest litter @ 5 t/ha and vermicompost @ 5 t/ha, gave significantly higher value than rest of the treatments under the cropping system. Maximum net returns ( 19.4 × 10³/ha) and benefit: cost ratio (2.1) amongst the chemical treatment, was observed with 100% RDF (maize) + 50% RDF (yellow sarson). Application of organic nutrient sources revealed that maximum net returns ( 17.6 × 10³/ha) and benefit: cost ratio (2.4) was registered with the FYM @ 2.5 t/ha + vermicompost @ 1.25 t/ha + forest litter @ 2.5 t/ha.